1. Field of the Invention
The present invention relates to a process for the production of L-tryptophan (hereinafter referred to as tryptophan) by a fermentation process.
2. Description of the Prior Art
Heretofore, there has been known, as a process for the production of tryptophan, a process which comprises producing tryptophan from a tryptophan precursor, that is, anthranilic acid, indole or 3-indolepyruvic acid. In contrast to this, the present inventors developed a process for the production of tryptophan by a direct fermentation process from a carbon source such as sugar by using a microoganism belonging to the genus Brevibacterium or the genus Corynebacterium and having resistance to tryptophan analogs such as 5-methyltryptophan, 5-fluorotryptophan etc. (Japanese Patent Publication No. 18828/1973, French Patent Application Laid-open No. 2059715, Japanese Patent Application Laid-open No. 162771/1980). It was also made clear that the amount of tryptophan accumulated is increased by imparting nutrient requirements for phenylalanine, tyrosine etc. and resistance to analogs of phenylalanine or tyrosine to these stains (Japanese Patent Publications No. 18828/1973, French Patent Application Laid-open No. 2059715) or by imparting thereto resistance to serine analogs (Japanese Patent Application Laid-open No. 174096/1982).